Rapid response valve

ABSTRACT

A valve releases fluid from a high pressure source to a low pressure receiver and includes a housing (301) having a first cavity (312), a second cavity (313), an annular interior sealing surface (318), an elastomeric ring (303), a poppet (302) and an actuator (304) for controlling the poppet&#39;s axial movement disposed coaxially within the housing (301). The poppet has a substantially cylindrical side wall, forming an external sealing surface (317). The poppet has fluid channels (310) for channeling fluid from the first cavity (312) radially outward through at least one orifice (311) in the side wall. When closed, the elastomeric ring (303) contacts the exterior sealing surface (317) and the interior sealing surface (318) sealing the first cavity (312) from the second cavity (313). When open, the orifice (311) is disposed relative to the elastomeric ring (303) such that fluid exiting the orifice deforms the elastomeric ring (303) outwardly forming a gap (314).

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention generally relates to a device for releasing fluidfrom a relatively high pressure source to a relatively low pressurereceiver. More particularly, the invention relates to a valve forrapidly deflating pressurized containers, such as pneumatic vehicletires, to desired, predetermined pressures.

2. Background

Many conventional devices for relieving fluid pressure from a containerare known to exhibit undesirable characteristics. Such undesirablecharacteristics include slowness of pressure relief, instabilities oroscillations in the motion of valve components during pressure reliefresulting in high frequency noise (i.e., a "screech"), excessively highwear rate on sealing components, and short valve life. Additionally,conventional devices typically suffer from hysteresis during the openingand closing functions of the valve. This hysteresis leads to aninaccurate and unrepeatable threshold relief pressure. Therefore, a needexists for an accurate valve that can relief pressure quickly withoutoscillation and component wear. The present invention fulfills this needamong others.

SUMMARY OF THE INVENTION

The present invention relates to a valve for releasing fluid from arelatively higher pressure source to a relatively lower pressurereceiver. The valve comprises a housing having a first cavity, a secondcavity, and an annular internal sealing surface. The first and secondcavities are axially disposed, and the annular interior sealing surfaceis axially disposed between them. The first cavity also has a connectionmechanism for operatively connecting to the source. The valve alsocomprises an elastomeric ring and a poppet disposed coaxially within thehousing. The poppet has a substantially cylindrical side wall, at leasta portion of which is an external sealing surface. Additionally, thepoppet has fluid channels for channeling the fluid from the first cavityradially outward through at least one orifice in the side wall. Thepoppet is axially movable at least between a closed position and anopened position. In the closed position, the elastomeric ring contactsthe exterior sealing surface and the interior sealing surface such thatthe first cavity is hermetically sealed from the second cavity. In theopen position, the orifice is disposed relative to the elastomeric ringsuch that fluid radially exiting the orifice deforms the elastomericring outwardly forming a gap between the side wall and the elastomericring. The gap enhances the egress of fluid from the first cavity to thesecond cavity. The valve also comprises an actuator for controlling thepoppet's axial movement between the closed and open positions.

One preferred embodiment of the invention relates to a valve withselectable relief pressures. In yet another embodiment, the valveprovides visual indication of the pressure in the fluid container. Afurther embodiment provides for the input of fluid through the reliefvalve. These and other features and benefits of the present inventionwill be apparent to those skilled in the art upon consideration of thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference numerals refer to likeparts throughout different views. The drawings are schematic and notnecessarily to scale, emphasis instead being placed upon illustratingprinciples of the invention.

FIGS. 1a & 1b are schematic axial sectional views of the valvingmechanism according to principles of this invention in a closed and openposition respectively;

FIG. 2 is a schematic axial sectional view of an embodiment of theapparatus;

FIGS. 3a & 3b is an enlarged schematic axial sectional view of afragmental portion of the apparatus shown in FIG. 1 in an open andclosed position respectively;

FIG. 4 is a schematic axial sectional view of another embodiment of theapparatus of the invention;

FIG. 5 is a schematic axial sectional view of the apparatus shown inFIG. 4 at a different pressure setting;

FIG. 6 is a schematic depiction of a portion of a pressure-settingdevice of the apparatus shown in FIG. 4;

FIG. 7 is a schematic axial sectional view of another embodiment of theinvention shown in inactive state;

FIG. 8 is a schematic axial sectional view of the apparatus of FIG. 7shown in active state;

FIG. 9 is a schematic axial sectional view of yet another embodiment ofthe invention;

FIG. 10 is a schematic axial sectional view of a further embodiment ofthe invention at a higher pressure setting;

FIG. 11 is a schematic axial sectional view of the apparatus of FIG. 10shown at a lower pressure setting;

FIG. 12 is a schematic axial sectional view of yet a further embodimentof the invention shown in active state at regulated pressure value (andindicating this value);

FIG. 13 is a schematic axial sectional view of the apparatus of FIG. 12shown in active state at a subnormal pressure value (and indicating thisvalue);

FIG. 14 is a schematic axial sectional view of still another embodimentaccording to principles of the invention shown in active state with ahigher pressure setting at regulated pressure value (and indicating thisvalue);

FIG. 15 is a schematic axial sectional view of the apparatus of FIG. 14shown in active state with a higher pressure setting at a subnormalpressure value (and indicating this value);

FIG. 16 is a schematic axial sectional view of the apparatus of FIG. 14shown in active state with a lower pressure setting at a subnormalpressure value (and indicating this value);

FIG. 17 is a schematic depiction of a portion of a pressure-settingdevice of the apparatus shown in FIG. 14;

FIG. 18 is a schematic axial sectional view of another embodiment of theinvention shown in inactive state; and

FIG. 19 is a schematic axial sectional view of the apparatus of FIG. 18shown in active state.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The present invention relates to a device for releasing fluid from arelatively higher pressure source to a relatively lower pressurereceiver. As used herein, the term "fluid" broadly refers to liquids orgases, or combinations thereof. The terms "source" and "receiver"broadly refer to any fluid environment such as the open atmosphere, orany container including rigid structures such as metallic and compositeair tanks, or flexible enclosures such as rubber tires and balloons. Forexample, the source may be a pressurized tank and the receiver may bethe atmosphere. Conversely, the source may be the atmosphere and thereceiver may a tank under vacuum. The only restriction on the source andreceiver is that the source be at a higher initial pressure than thereceiver.

In its basic embodiment, the invention involves a valve comprising (1) ahousing, (2) an elastomeric ring, (3) a poppet, and (4) actuation means.These elements are described below in light of FIGS. 1A & 1B, whichdepict a schematic cross-sectional view of the valve in a closed andopened position respectively.

1. Housing

The housing 301 is separated into a first cavity 312 and a second cavity313 which are axially disposed. Disposed between the first and secondcavities 312, 313 is an annular interior sealing surface 316 adapted toform a seal with the elastomeric ring 303. The term annular as usedherein broadly refers to circular, nearly circular, ovular, elliptical,or similar shapes. The housing may be integral or a combination ofdiscrete components.

The housing also has connection means for operatively connecting thefirst cavity to the source. The connection means employed depends uponthe source and may range from simple threads on the inside of thehousing to a valve assembly having sequencing and control features.

To prevent the elastomeric ring's axial movement within the housing, itis preferable to employ restraining means. The restraining meansdepicted in FIGS. 1A and 1B involves an annular groove to receive andsecure the elastomeric ring 303. In this embodiment, the annular groovecomprises the interior sealing surface 316, a housing shoulder 306, anda backup ring 307 held in place by a second shoulder 319. It should alsobe understood that other annular grove configurations are possible aswell as other restraining means in general. For example, other suitablerestraining means include a groove recessed into the housing, variouscombinations of shoulders/ridges and a backup ring, and high frictiontexturing or adhesive. Moreover, the retaining means can be discrete orintegral to the housing, and different approaches may be used incombination or individually.

2. Elastomeric Ring

The elastomeric ring comprises an essential element for hermeticallysealing the first cavity 312 from the second cavity 313. The term "ring"as used in this disclosure broadly refers to O-rings, gaskets, and otherdeformable seals having an annular shape. For descriptive purposes, theseal 303 is divided roughly hemispherically into a first and secondportion 308, 309, as shown by the dotted line. The first and secondportions 308, 309 correspond in orientation to the first and secondcavities 312, 313.

3. Poppet

The poppet 302 is disposed coaxially in the housing 301 and extendsbetween the first and second cavities 312, 313. It has a substantiallycylindrical side wall 316, a portion of which is an exterior sealingsurface 317. The term cylindrical as used herein broadly describes athree dimensional figure having a circular, nearly circular, ovular,elliptical or similar cross-sectional shape.

The poppet 302 also comprises fluid channeling means 310. The fluidchanneling means as used herein broadly refers to slots, orifices,baffles, conduit, passageways, permeable membranes, or any other meansfor guiding fluid flow. The fluid channeling means enables fluidcommunication between the first and second cavities when the poppet isan opened position (discussed below). More specifically, the channelingmeans 310 directs the fluid 315 such that it enters the poppet 302 fromthe first cavity 312 and exits substantially radially from at least oneorifice 311 in the side wall 316.

The poppet 302 is axially moveable within the housing to at least anopen position (as shown in FIG. 1A), and a closed position (as shown inFIG. 1B). When said poppet is in the closed position (FIG. 1A), theorifice 311 is proximate to the first portion 308. Fluid from the firstcavity 312 therefore is able to exert pressure on the first portion ofthe seal 303 via the channeling means 310 and radial orifice 311. Thispressure urges the elastomeric ring 303 toward the backup ring 307causing the elastomeric ring 303 to deform such that it contacts boththe interior and exterior sealing surfaces 306, 317, therebyhermetically sealing the first cavity 312 from the second cavity 313. Inaccordance with conventional "O" ring seal designs, the sealing effectbecomes more positive with increasing pressure in the first cavity 312providing the poppet 302 remains in the closed position.

When the poppet 302 is in the open position (FIG. 1B), the orifice 311is proximate to the second portion 309. Fluid 315 enters the fluidchanneling means 310 of the poppet 302 from the first cavity 312 andradially exits from the side wall 316 through the orifice 311. Since theexterior sealing surface 317 of the poppet 302 has been displaced and nolonger contacts the elastomeric ring 303, fluid is free to flow past theelastomeric ring 303 to the second cavity 313. This flow is directedsubstantially radially against the elastomeric ring 303, which promotesthe formation of a gap 314 between the elastomeric ring 303 and the sidewall 316. The formation of the gap 314 provides for improved egress offluid from the source.

4. Actuation Means

The movement of the poppet 302 within the housing 301 is controlled bythe actuation means 304. The configuration and functionality of theactuating means depends upon the application. In pressure regulationapplications, for example, the movement of the poppet can be a functionof force equalization between a fluid pressure force and an urgingforce.

The fluid pressure force results when the source is operativelyconnected to the first cavity and its higher pressure fluid exertspressure on the poppet since the poppet is partially disposed in thefirst cavity. This pressure has the effect of urging the poppet towardthe second cavity.

Countering this force is urging means, such as springs or elastomericmaterial. The urging means is operatively connected to the poppet suchthat it urges the poppet toward the first cavity.

If the fluid pressure in the first cavity is greater than the urgingforce, then the poppet will shift toward the second cavity into the openposition as shown in FIG. 1b. When the poppet moves into the openposition, the exterior sealing surface 317 no longer contacts theelastomeric ring 303 allowing fluid to flow from the first cavity 312past the elastomeric ring 303 and into the second cavity 313. As theflow develops, the elastomeric ring 303 deforms radially outward therebyincreasing the gap 314 available for fluid flow.

If left to force equalization, the poppet will return to the closedposition after enough fluid has exited the first cavity to reduce thepressure on poppet below that exerted by the urging means. As the valvecloses, radial fluid flow against the elastomeric ring 303 decreasesallowing it to return to its non-deformed shape. In the closed positionshown in FIG. 1a, the exterior sealing surface 317 and the interiorsealing surface 318 again contact the elastomeric ring 303 tohermetically seal the first cavity 312 from the second cavity 313.

The ability of the fluid to deform the elastomeric ring 303 outwardlyand increase a fluid egress from the first cavity 312 provides for avalve that requires very little axial movement for actuation. To openthe valve, the poppet travels less than the height of elastomeric ringsuch that the orifice moves from the first portion of the elastomericring to the second portion. Such minor travel incurs little frictionallosses, and, thus, the pressure at which valve opens/closes isrepeatable within a small error.

On the other hand, since the fluid pressure must be high enough not onlyto move the poppet, but also to deform the seal, a certain amount ofhysteresis is present in the system which increases its stability. Thishysteresis prevents the valve from vacillating between the open andclosed position each time there is a slight change in the pressure ofthe source. Thus, if the valve is connected to a tire, it would have acertain amount of resistance to opening each time the tire experience aroad shock.

It should be understood that although the present invention isparticularly well suited for pressure equalization actuation, othertypes are possible such as mechanical actuation, a combination ofmechanical actuation and equalization actuation, and timed actuation.

Specific embodiments of the present invention will now be considered inFIGS. 2-19 in light of the principles of the invention discussed above.It should be understood that the particular valves disclosed are fordemonstrative purposes and should not be construed to limit the scope ofinvention. Moreover, the particular aspects of each embodiment may bevaried and interchanged with other embodiments to form a multitude ofcombinations.

Referring now to FIG. 2 of the drawings, there is depicted a reliefvalve 10 that comprises a generally hollow cylindrical housing assembly12, an axially movable valve poppet assembly 14 disposed coaxiallywithin housing 12, sealing means 28 and actuating means including springloading means 16 being at least partly disposed within the housing 12.

Housing assembly 12 comprises a first and second cavity 18, 38, anannular seat 20, an annular cylindrical internal seal surface 22disposed near and above seat 20, and a annular retention shoulder 23adjacent to surface 22. Relief valve 10 is intended to be connected to acontainer of pressurized fluid, for instance, a pneumatic tire. For sucha purpose, the first cavity 38 of housing 12 has connection means to acontainer of fluid. Connection means are known in the art and mayinclude an O-ring seal and a female thread adapted for receiving aconventional tire valve stem.

In this embodiment, housing assembly 12 further includes at least onevent orifice 50 and an elastomeric (or rubber) tubular that covers thevent orifices. When fluid is vented from orifice 50, the fluid pressuretends to lift up sleeve 52 from its seating and allows fluid to escape.To promote fluid escape, sleeve 52 can be provided with at least oneslit 54 that is normally closed, but opens elastically in response tovent pressure. The sleeve prevents entry of dirt into the valve.

Sealing means 28 includes a seal 29, shown here in form of anelastomeric O-ring disposed between the interior sealing surface 22 andthe exterior sealing surface 26. The seal 29 provides for dynamicsealing between movable poppet 14 and the housing 12 while the poppet isin its closed position.

Valve poppet assembly 14 comprises fluid channeling means 34 for ventingfluid from first cavity 38. In this embodiment, fluid channeling means34 includes an annular orifice 36 that is disposed between outer surface32 and exterior sealing surface 26. When poppet 14 is in the openposition, the seal between exterior sealing surface 26 and the seal 29(and thereby between surface 26 and seal surface 22) is broken allowingfluid to pass through the orifice 36 and into the second cavity. Fluidflow through the orifice 36 is directed substantially radially outwardlyagainst the O-ring seal 29 which elastically deforms substantiallyradially outwardly and in a direction away from sealing contact with theexterior sealing surface 26. This creates an annular gap 40 betweensurface 26 and seal 28. The egress of fluid from the pressurizedcontainer is thereby enhanced by the annular gap.

Valve poppet assembly 14 comprises a travel stop 24 that seats againstseat 20 while poppet 14 is at the extreme lower end of its axialmovement. Valve poppet 14 further comprises a cylindrical exteriorsealing surface 26 disposed near stop 24 above seat 20. Surface 26 canbe of a low-friction plastic material to provide advantageous operatingcharacteristics for the relief valve. In this particular embodiment, thepoppet is in its closed position when its stop 24 is against or nearseat 20, and in the opened position when its stop 24 is distal from theseat 20.

Valve poppet assembly 14 further includes restraning means 30 torestrain seal 29 from deforming excessively under flow forces whilepoppet 14 is in an open position. In this embodiment, restraining means30 includes a cylindrical outer surface 32 that contacts the O-ring 28while the poppet has lifted from seat 20. Outer surface 32 can be of alow-friction plastic material to provide advantageous operatingcharacteristics for the relief valve.

Actuating means includes spring loading means 16 having a compressionspring 42, and an actuating device 44 having an activating pin 46 and apush rod 48. Spring 42 extends between activating pin 46 and poppet 14and preloads the poppet axially downwardly toward seat 20. Actuatingdevice 44 is borne within housing 12 to facilitate limited axialtranslation and rotation of activating pin 46. For instance, when therelief valve is connected to a standard tire valve stem of a pressurizedtire, downward axial translation of pin 46 causes push rod 48 to extendinto the tire valve stem and to depress and open the tire valve. Whenthe tire valve is opened, the first cavity 38 is exposed to the fluidpressure in the tire. In this manner, actuating device 44 and, morespecifically, activating pin 46 and push rod 48 are operative as meansfor exposing the poppet 14 to the pressurized fluid, and consequentlyforcing poppet 14 against the loading of spring 42. Moreover, theactivating pin 46 can serve as a means for indicating the release ofpressurized fluid into the first cavity since its axial movementrelative to the housing is visually detectable. Limited rotation ortwist of pin 46 provides for holding and locking of the pin in itsextended axial position.

The means for locking the activating means in activation position holdsand locks pin 46 (and therewith rod 48) in activation position. Themeans for locking comprises a circular groove 55 in pin 46, two flatsopposed to one another on the periphery of pin 46 beneath groove 55, twodowels 57 fixed radially in housing 12, and a stop pin 58 fixed radiallythrough pin 46 in groove 55 (and protruding above bottom of groove 55).Depression of pin 46 moves flats 56 past dowels 5 groove 55 is alignedwith the dowels 57. Subsequent turning or twisting of pin 46 engagesdowels 57 in groove 55 against axial motion. Pin 46 is twisted (forinstance 90 degrees) until stop pin 58 contacts dowels 57. Thus,actuating means 16 (specifically 44) is locked in actuating positionwhereby push rod 48 (attached to pin 46) holds open the t valve and isthereby operative as means for exposing poppet 14 to pressurized fluid.

Referring to FIGS. 3A & 3B, the operation of the valve will now bediscussed in light of an enlarged depiction of the valving region ofvalve 10 of FIG. 2. In FIG. 3a, the poppet 14 is shown in the openedposition. Consequently, the orifice 36 is substantially proximate to thesecond portion 2 of the O-ring 29. In the preferred embodiment, theportion of the channelling means 34 that radially extends outward towardthe orifice 36 is narrower than the inlet. This causes the exiting fluidto increase in velocity, thereby enabling the channeling means to act asa nozzle or other means for forming a fluid jet. By virtue of the fluidjet radially extending from orifice 36, the O-ring is deformed. Thisflow, directed radially against O-ring 29, deforms at least a portion ofthe O-ring substantially to the indicated shape. As can be seen, thisdeformation promotes formation of a substantially larger annular gap 40than if vent flow had not been issued from channel 36 against theO-ring. The creation of the annular gap 40 by the exiting fluid flowprovides for fast ventilation. Furthermore, as a consequence of thedeformation of the O-ring by flow directed against it from channelingmeans and of the resulting increased annular gap 40, it has been foundthat poppet vibration, poppet instabilities, screeching noises, and thelike, and the associated wear of valve parts are avoided orsignificantly reduced. These are important advantages of the invention.

FIG. 3B depicts the valve 10 in a closed state. In the closed state, thepoppet 14 moves into the closed position wherein the orifice 36 isproximate to the first portion 1 of the O-ring seal 29. Fluid flow inthis configuration tends to urge the O-ring against the back-up ring 23and the interior and exterior sealing surfaces, thus sealing the firstcavity from the second cavity. FIG. 3B also shows the preferredembodiment wherein a back-up ring 23 is employed. The back-up ring 23not only holds the O-ring in place to prevent its axial movement, butalso tends to channel fluid around its periphery. This creates a forcethat urges the seal against the interior sealing surface 22 and reducesthe wear on the O-ring caused by it being drawn into the gap 40.

Referring now to FIGS. 4-6, there is shown an embodiment of theinvention, namely valve 60, that enables a user to select any one ofthree predetermined relief pressures and allows inflation through therelief valve 60. In the preferred embodiment, the conventional tirecheck valve is removed from the tire valve stem and is mounted withinthe upper inlet stem 64 and relief valve 60 is sealedly mounted upon thetire valve stem. Inflation of the tire can now be performed throughinlet stem 64 (through relief valve 60) in a conventional manner. Thus,the means for inflating a tire directly through the relief valve 60includes inlet stem 64, the axial bore of upper end closure 72, flowtube 62, and mounting and connecting means 38.

The lower portion of the relief valve 60 is substantially identical tothe lower portion of the relief valve 10 depicted in FIG. 2, with theexception that push rod 48 (of FIG. 2) is replaced by a flow tube 62 (inFIGS. 4 and 5) that is not axially movable relative to housing 12. Asfar as the lower portions of the relief valve are concerned, thedescription provided hereinbefore in regard to the embodiment specifiedin conjunction with FIGS. 2-3 (relief valve 10) is also applicable tothe embodiment shown in FIGS. 4-6.

The remaining central and upper portions of relief valve 60 are ofsomewhat different structure. As indicated before, valve 60 facilitateschoosing one of three possible predetermined spring loading magnitudesfor poppet 14. Means for choosing, means for registering and holding,and means for visually displaying a chosen spring loading magnitudeinclude the following components upper outer housing 70, upper endclosure 72, cylindrical sleeve cam 74, cam cover 76, spring rod lifterplate 78, upper dirt guard 80, primary guide 82, secondary guide 84,tertiary guide 86, lifter rods 88, primary spring 90, secondary spring92, tertiary spring 94, flow tube 62, seal 96, upper spring guide 98,dowels 99, and dirt guard rivet 100.

FIG. 4 shows relief valve 60 with all three springs loading poppet 14downwardly via primary guide 82. Hence the pressure relief setting hasthe highest magnitude, as the sum of the three spring forces (springs90,92,94) is in effect. When the cylindrical sleeve cam 74 is lifted androtated along with the cover 76 from the P1 to the P2 position (see alsoFIG. 6), cam 74 and thereby also lifter plate 78 are forced upwardly.Lifter rods 88 are thereby raised and, therewith, the tertiary guide 86disengages the tertiary spring 94 from primary guide 82, and thus, alsofrom the poppet. The spring force acting on the poppet is now only thesum of the forces of the primary spring 90 and the secondary spring 92.Upon lifting and rotating of the cam to the P3 position, the lifterplate 78 is raised further and therewith also lifter rod 88 which causestertiary guide 86 to contact and raise secondary guide 84 and, thereby,disengage from primary guide 82. The latter state is shown in FIG. 5,wherein only the force of the primary spring 90 remains effectiveagainst the poppet.

FIG. 6 schematically illustrates cylindrical sleeve cam 74 (in unrolledflattened depiction) in relation to dowels 99 for the three possiblespring loadings of poppet 14 that correspond to the three possiblesettings of relief pressures (P1, P2, P3). Dowel 99 is shown here ineach of the three setting positions for clarity's sake. However, itshould be understood that, in actuality, dowel 99 can be disposed onlyin one of the positions for a particular setting. Means for visuallydisplaying a chosen relief pressure value includes the rotatablecylindrical sleeve cam 74 in relation to dowels 99 and/or in relation tothe upper dirt guard 80 together with the externally protruding portionof the upper end closure 72. Suitable visible markings upon exposedsurfaces of these components to indicate relative rotational positionand therewith the selectable pressure settings provide display of thechosen and the available pressure settings. Although the embodimentdepicted herein teaches a valve with predetermined spring settings, itshould be understood that an embodiment having a dial for continuoustension settings within a range of minimum and maximum spring settingsis well within the scope of the invention.

Referring now to FIGS. 7-8, there is depicted another embodiment of theinvention in the form of a relief valve 102. Like valve 60, relief valve102 is substantially identical to the embodiment shown in FIG. 2, anddescribed in conjunction therewith, except for a variation of actuatingmeans. The actuating means 16 comprises an actuating device 44 having anactivating pin 46 and a push rod 48 as described in conjunction withFIG. 2, but spring 42 (of FIG. 2) is now replaced by threeconcentrically disposed springs that act in unison as spring loadingmeans--namely, inner spring 104, central spring 106, and outer spring108. Spring 104 extends between activating pin 46 and poppet 14 andsprings 106 and 108 extend between internal shoulder 110 of housing 12and poppet 14. Poppet 14 is therefore preloaded axially toward the firstcavity within housing assembly 12.

As described in light of FIGS. 4 & 5, employment of multiple springs inthis manner facilitates providing different spring-loading magnitudeswithout a need to stock larger numbers of individual springs of specificspring constants. For instance, if springs 108 and 106 are left out, therelief valve's preset pressure will correspond to a spring loading byspring 104 (when valve 102 is activated by actuating device 44). Ifspring 104 and one of the springs 106 or 108 are installed, the combinedrespective spring loadings will be in effect.

Relief valve 102 is shown with housing 12 having mounting and connectingmeans 38 appropriately adapted for mounting on a tire valve stem thatincludes a standard tire valve. FIG. 7 shows relief valve 102 in aninactive state; i.e. the tire valve is not opened and the relief valveis not exposed to tire pressure. FIG. 8 shows relief valve 102 in anactive state; i.e. the tire valve is opened by the push rod 48 extendinginto the tire valve stem. Activation is performed manually by pushingdown (and twisting) the activating pin 46. In operation, when pressureis relieved from the tire, excess tire pressure forces poppet 14 to liftfrom seat 20, thereby facilitating relief of container pressure byventing of fluid therefrom in the manner hereinbefore described inconjunction with FIGS. 1-3.

Referring now to FIG. 9, relief valve 112 is shown. Relief valve 112 issubstantially identical to the embodiment shown in FIG. 2 and describedin conjunction therewith except that the actuating device 44 (of FIG. 2)differs somewhat in structure from the actuating device 114 (of FIG. 9)and that spring 42 (of FIG. 2) is now replaced by a spring 116. In thisembodiment, actuating device 114 also includes an activating pin 118having a knob 120 attached at one end, a push rod 122 affixed to theother end of pin 118, and spring loading and locking means 124 disposedin the region of the lower end of pin 118.

In FIG. 9, spring 116 extends between shoulder collar 126 (part ofhousing assembly 128) and poppet 14. Poppet 14 is thus preloaded axiallydownward within housing assembly 128. Spring loading and locking means124 includes a spring 130 that extends between shoulder 126 andactivating pin 118. Activating pin 118 is consequently spring loadedupwardly (toward its inactive position).

Relief valve 112 is shown with housing assembly 128 having mounting andconnecting means 38 appropriately adapted for mounting on a tire valvestem that includes a standard tire valve. FIG. 9 shows relief valve 112in an inactive state; i.e. the tire valve is not opened and the reliefvalve is not exposed to tire pressure. In order to activate valve 112,knob 120 is manually depressed and twisted. Consequently, a tire valveis opened by the push rod 122 extending into the tire valve stem. Hence,the first cavity of the poppet assembly 14 is thereby exposed to tirepressure. In operation, when pressure is relieved from the tire, excesstire pressure forces poppet 14 to lift upwardly, thus relievingcontainer pressure by venting of fluid as described in conjunction withFIG. 2.

Referring now to FIGS. 10 and 11, there is shown another embodiment,namely relief valve 132, which provides for tire inflation through thevalve and for selective setting to any one of three predetermined reliefpressures. Structurally and functionally, valve 132 is substantiallyidentical to the valve described in conjunction with FIGS. 4-6 with theexception of the actuating means, particularly, the arrangement oflifter rods 88 and tertiary guide 86 (for tertiary spring 94). Theselifter rods and the guide are replaced in FIGS. 10 & 11 by a lifter cup134 that is slotted for dowels 99. Cup 134 provides substantially thesame function as the components it has replaced.

Referring to FIG. 10, the relief valve 132 is shown with all threesprings loading poppet 14 downwardly. Hence the pressure relief settinghas the highest magnitude, as the sum of the three spring forces(springs 90,92,94) is in effect. When the cylindrical sleeve cam 74 islifted and rotated along with the cover 76 from the P1 to the P2position (see also FIG. 6), cam 74 and lifter cup 134 are forcedupwardly. Tertiary spring 94 is thereby disengaged from primary guide 82and thusly also from the poppet 14. The spring force acting on thepoppet is now only the sum of the forces of the primary spring 90 andthe secondary spring 92. Upon lifting and rotating of the cam to the P3position, lifter cup 134 is raised further and lifts secondary guide 84,whereby also the secondary spring 92 is disengaged from primary guide 82and therewith also from poppet 14. The latter state is shown in FIG. 11,wherein only the force of the primary spring 90 remains effectiveagainst the poppet.

Valve 132 also includes a sleeve cam 74 that is substantially identicalto cam 74 of relief valve 60 and that functions identically. In thisrespect, referring back to FIG. 6, there is schematically illustratedcylindrical sleeve cam 74 (in unrolled flattened depiction) in relationto dowels 99 for the three possible spring loadings of poppet 14 thatcorrespond to the three possible settings of relief pressures (P1, P2,P3). As indicated hereinbefore, valve 132 facilitates choosing one ofthree possible predetermined spring loading magnitudes for poppet 14.Means for choosing, means for registering and holding, and means forvisually displaying a chosen spring loading magnitude include the abovecomponents.

During installation on a tire, the conventional tire check valve isremoved from the tire valve stem and is mounted within the uppermostinlet stem 64. Relief valve 132 is then mounted (by means 38) upon thetire valve stem. Inflation of the tire can now be performed throughinlet stem 64 (through relief valve 132) in conventional manner. Thus,the means for inflating a tire directly through the relief valve 132includes inlet--stem 64, flow tube 62, and mounting and connecting means38.

Referring now to FIGS. 12 and 13, there is depicted another embodiment,namely relief valve 140 that provides excess pressure relief, pressureindication, and fill-through capability. Relief valve 140 comprises ahousing 142, a poppet 144, spring loading means 146, and sealing means148. Housing 142 includes a cavity 150 and therein a cylindricalinternal seal surface 152. Poppet 144 is coaxially movable within cavity150 and includes a body 153 having a valving region 154 at its loweraxial end (first axial end 155) and a loading region 156 at a secondaxial end 157 spaced axially upwardly from valving region 154. Poppet144 includes in the valving region 154 a cylindrical exterior sealingsurface 158 that extends between the valving region 154 and the loadingregion 156.

Sealing means 148 includes an O-ring 160 of resilient material. TheO-ring 160 is disposed and retained upon internal seal surface 152 andis shown while sealing against exterior sealing surface 158 (in FIGS.12,13). Housing 142 further comprises connecting means 162 at the lowestend for mounting and sealedly connecting valve 140 to a tire valve stem.Means 162 includes an actuator rod 164 to push against the valve of astandard tire valve and thereby open the tire valve while the reliefvalve 140 is affixed to the tire valve stem. Thus, connecting means 162can also act as actuating means in that it exposes the bottom end ofpoppet 144 to tire pressure.

Housing 142 also comprises an outer casing 166 and threaded thereon isan upper flange 167 having vent openings 168 and a vent cover 170 toprotect against entry of dirt. Vent cover 170 is of a resilient materialand can include normally closed slits that open in response to ventpressure to release flow outwardly to ambient, yet dirt is preventedfrom entering as the slits close in the absence of internal, ventpressure. Cover 170 can be provided without such slits and rely upon itselastic properties to release vent flow by opening an annular area atits middle periphery in response to internal vent pressure. Upper flange167 serves to support the upper end of the compression spring of springloading means 146. The threaded fastening of flange 167 in casing 166 ofhousing 142 permits fine adjustment of the spring loading, for instanceduring tests on assembly of the valve.

Poppet 144 also includes an extension 172 that reaches to the outside ofhousing 142 and extends beyond the housing's uppermost end. An axialconduit or bore 174 extends throughout the length of poppet 144. Theuppermost end of extension 172 is formed internally and externallyidentically to a conventional tire valve stem to facilitate screwing inof a standard tire valve 176 and to provide an appropriate couplingfacility to a pneumatic hose to inflate a tire through relief valve 140.Extension 172 includes markings 178 that serve to indicate visuallyfluid pressure conditions in a tire (by their position in relation tohousing 142).

Poppet 144 includes means for bypassing the O-ring seal 160 (of sealingmeans 148) when excess pressure is being relieved. The bypassing meansincludes a bypass passage 180 that leads from the region beneath thelower axial surface of poppet 144 to exterior sealing surface 158.Bypass passage 180 includes a conduit in the form of at least one bore182 and a substantially radially directed channel 184 leading therefromthrough surface 158. Channel 184 acts as means for forming a fluid jetdirected against O-ring 160 when fluid flows therethrough.

For the purpose of describing operation of relief valve 140, let usassume that valve 140 is connected to a tire valve by connecting means162 and that poppet 144 is therefore exposed to tire pressure (frombeneath).

Relief valve 140 is shown in FIG. 12 in an active state corresponding toa desired normal tire pressure; i.e. the valve is closed and markings178 indicate presence of this normal pressure. Spring loading means 146is preset to exert onto poppet 144 a downward spring loading force thatbalances the upwardly-acting tire pressure if the tire pressure is ofthe desired normal magnitude. In other words, means for force-balancingthe poppet includes the downwardly-acting force of spring loading means146 and the upwardly-acting force of the tire pressure. The forcebalancing operation includes the axial movement of poppet 144 in adirection so as to diminish the force difference; the force differencebeing defined as the difference between the spring force (loading means146) and the pressure force due to tire pressure. Means for exposing thepoppet 144 to tire pressure includes actuator rod 164 and connectingmeans.

Supposing that valve 140 has just been attached to a tire containingexcess pressure (above desired normal pressure) therein or that thepressure in the tire has been raised to excess after valve 140 has beenattached thereto. Excess pressure will force poppet 144 upwardly fromthe shown position. Flow exiting out of channel 184 at the sealingsurface 158 in valving region 154 will move upwardly so as to produce agap between sealing surface 158 and O-ring 160, i.e. this gap opens in adirection toward cavity 150. Consequently, fluid flow (relief flow) fromthe tire will pass through passage 180, through the gap, through cavity150, and via vent openings 168 through or past vent cover 170 toambient. As the excess tire pressure quickly diminishes to the normalpressure level, poppet 144 will be forced downwardly again by springloading means 146; channel 184 will no longer bypass sealing means 148(O-ring 160); venting of tire flow will cease; and, relief valve 140will again attain the force-balanced state shown in FIG. 12.

Referring now to FIG. 13, relief valve 140 is shown here in an activestate corresponding to a subnormal tire pressure; i.e. the valve isclosed and the relative position of markings 178 (almost hidden)indicate presence of this subnormal pressure. As depicted, thecompression spring of spring loading means 146 forces poppet 144downwardly against the subnormal pressure until force-balancing resultsor until poppet 144 reaches the bottom stop of its travel. Hence, avisual indication corresponding to the tire pressure is provided by theprotrusion of extension 172 (or of marking 178) relative to housing 142.

A tire provided with relief valve 140 that indicates subnormal pressurecan be re-inflated through poppet extension 172 (and valve 176) todesired normal pressure. Should excess pressure result during inflation(as it often happens), relief valve 140 will relieve the excesspressure, as described before particularly in conjunction with FIGS. 3aand 3b.

Referring now to FIGS. 14-17, there is illustrated yet a furtherembodiment of the invention, namely relief valve 190, that provides forselective setting to any one of three predetermined relief pressures andprovides tire pressure indication. In many structural and functionalaspects, relief valve 190 is similar to relief valve 132 discussed inconjunction with FIGS. 10 and 11. A significant difference, however, isthat valve 190 does not offer a fill-through capability, but providespressure indication. Relief valve 190 comprises a housing 192, a poppet194, spring loading means 196, and sealing means 198. Housing 192includes a cavity 200 and therein a cylindrical, internal seal surface202. Poppet 194 is coaxially movable within cavity 200 and includes abody 203 having a valving region 204 at its lower axial end (first axialend 205) and a loading region 206 at its second axial end 207 spacedaxially upwardly therefrom. Poppet 194 includes in the valving region204, a cylindrical exterior sealing surface 208 that extends between thevalving region 204 and the loading region 206.

Sealing means 208 includes an O-ring 210 of resilient material. O-ring210 is disposed and retained upon an internal seal surface 202 and isshown while sealing against exterior sealing surface 208. Housing 192further comprises connecting means 212 at the lowest end for mountingand sealedly connecting valve 190 to a tire valve stem. Means 212includes an actuator rod 214 to push against the valve of a standardtire valve and thereby open the tire valve while the relief valve 190 isaffixed to the tire valve stem.

Housing 192 also comprises an outer casing 216 and fastened thereon isan upper flange 217. Radial vent openings 218 are provided in casing216. A vent cover 220 in form of a cylindrical shell of elastic material(for instance rubber) to protect against entry of dirt is disposed aboutouter casing 216. Expandable vent cover 220 is of resilient material andcan include normally closed slits that open in response to vent pressureto release flow outwardly to ambient, yet dirt is prevented fromentering as the slits close in the absence of internal vent pressure.Cover 220 can be provided without such slits and rely upon its elasticproperties to release vent flow by opening at one or both of its ends inresponse to internal vent pressure. Upper flange 217 serves to supportthe upper ends of compression springs 221, 221', 221" of spring loadingmeans 196.

Poppet 194 also includes an extension 222 that reaches to the outside ofhousing 192 and extends beyond flange 217 at the housing's uppermostend. Extension 222 can include peripheral markings 228 to visuallyindicate (by their position in relation to flange 217) fluid pressureconditions in a tire. Poppet 194 includes means for bypassing the sealprovided by O-ring 210 (of sealing means 198). This bypassing meanscomprises a bypass passage 230 that leads from the region beneath thelower axial face of poppet 194 to exterior sealing surface 208. Bypasspassage 230 includes a conduit in the form of at least one bore 232 anda substantially radially directed channel 234 leading therefrom throughface 208.

For the purpose of describing operation of relief valve 190, assume thatvalve 190 is connected to a tire valve by connecting means 212 and thatpoppet 194 is therefore exposed to tire pressure (from beneath). Reliefvalve 190 is shown in FIG. 14 in an active state corresponding to adesired normal tire pressure; i.e. the valve is closed and markings 228indicate presence of this normal pressure. Force-balancing meanscomprises spring loading means 196 to exert onto poppet 194 a downwardspring loading force and the upwardly-acting force of the tire pressure.The force-balancing operation includes the axial movement of poppet 194in a direction so as to diminish the force difference; the forcedifference being defined as the difference between the spring force(loading means 196) and the pressure force due to tire pressure. Meansfor exposing the poppet 194 to tire pressure includes connecting means212 and actuator rod 214. As shown in FIG. 14, all three springs(221,221',221") are active and force poppet 194 downwardly--the downwardforce being balanced by the force due to the tire pressure that actsonto the poppet in upward direction.

Supposing that valve 190 has just been attached to a tire containingexcess pressure (above desired normal pressure) therein or that thepressure in the tire has been raised to excess after valve 190 had beenattached thereto. Excess pressure will force poppet 194 upwardly fromthe shown position. Flow exiting out of channel 234 at the sealingsurface 208 in valving region 204 will move upwardly so as to produce agap between sealing surface 208 and O-ring 210, i.e. this gap opens indirection toward cavity 200. Consequently, fluid flow (relief flow) fromthe tire will pass through passage 230, through the gap, into cavity200, and via vent openings 218 through or past vent cover 220 toambient. As the excess tire pressure quickly diminishes to the normalpressure level, poppet 194 will be forced downwardly again by springloading means 196, flow through channel 234 will no longer be able tobypass sealing means 198 (O-ring 210), venting of tire flow will cease,and relief valve 190 will again attain the balanced state shown in FIG.14.

Referring now to FIG. 15, relief valve 190 is shown here in an activestate corresponding to a subnormal tire pressure; i.e. the valve isclosed and the relative position of markings 228 (almost hidden)indicate presence of this subnormal pressure (or absence of anypressure). As depicted, the compression springs of spring loadingmeans--196 force poppet 194 downwardly against the subnormal pressureuntil force-balancing results or until poppet 194 reaches the bottomstop of its travel. Hence, a visual indication corresponding to the tirepressure is provided by the protrusion of extension 222 (or of marking228) relative to housing 192 (flange 217).

Referring now to FIG. 16, relief valve 190 is set to a low reliefpressure setting whereby only primary spring 221 is in effect. Reliefvalve 190 is depicted in an active state corresponding to a subnormaltire pressure or to absence of any pressure. Housing 192 includes acylindrical sleeve cam 236 that has shaped slots 238. Flange 217 isprovided with radial pins 240 that reach through slots 238 along whichcam 236 can be slidingly rotated.

Referring now also to FIG. 17, there is schematically illustratedcylindrical sleeve cam 236 (in unrolled flattened depiction) in relationto pins 240 for the three possible spring loadings of poppet 194 thatcorrespond to the three possible settings of relief pressures (P1, P2,P3). As indicated hereinbefore, valve 190 facilitates selecting one ofthree possible predetermined spring loading magnitudes for poppet 194.Means for choosing, means for registering and holding, and means forvisually displaying a selected spring loading magnitude include theabove components. In contrast with the illustration of cam 74 in FIG. 6,the depiction of cam 236 in FIG. 17 reflects the increased lift travelbetween the pressure settings which is required to suit the increasedaxial travel of poppet 194 due to the provision for pressure indication(by relative position of poppet extension 222 versus flange 217 ofhousing 192).

With respect to the low pressure setting (P3) of valve 190 illustratedin FIG. 16, it can be seen that only spring 221" remains engaged againstloading region 206 of poppet 194 while the bottom ends of springs 221and 221' are disengaged and lifted upwardly by the action of cam 236 vialifter cup 242 and spring guide 244. Lifter cup 242 is slotted forradial pins 240. The pressure setting mechanism and action for valve 190closely parallel those described hereinbefore for relief valve 132 inconjunction with FIGS. 10 and 11.

An annular dirt guard 246 of resilient rubber-like material closes offthe annular space between flange 217 and sleeve cam 236, yet permitsrotation and axial translation of flange 217, as required for pressuresetting.

FIGS. 18 and 19, depict yet another embodiment of the present invention.This embodiment is similar in many respects to the single pressure,manually activated deflator valve described in FIG. 9, however, thisversion incorporates a sequential activation means. The sequencing meansincludes (a) a means of locking the main poppet in a sealed positionprior to activation, (b) a means of fully opening the tire stem corevalve, (c) a means of releasing the deflator valve main poppet to permitregulation to the desired tire pressure, and (d) a means of locking thedeflator valve activation mechanism in the operational position. Thesequencing means and its components will now be considered in light ofthe preferred embodiment of FIGS. 18 and 19, although it should beunderstood that the other configurations are possible.

Referring to FIG. 18, which shows the deflator valve before actuation,the main poppet spring 425 preset load is set by adjustment of thespring reset ring 417 which threads into housing 401. A locking pin 428holds the poppet spring guide 406 in place preventing the poppet 405from opening before actuation. The locking pin 428 is guided by a sleeve427 in the retaining ring 419 which also screws into the valve housing401 and is pinned in place with pin 430, and which also has alongitudinal slot cut into the inner diameter allowing the extension ofthe lower pin 421 to slide axially when the actuating pin 407 is pusheddownward against spring 429. The lower end of spring 429 is held inplace by the upper retaining ring 408 which screws into the valvehousing 401 and is pinned in place with pin 430.

This upper retaining ring 408, along with the lower retaining ring 419,holds the pin actuator cylinder 424 in place without restricting rotarymotion. The pin actuator cylinder 424 initially holds the poppet lockingpin 428 in place preventing the poppet 405 from opening. The pinactuating cylinder 424 also has a longitudinal groove cut into the innerdiameter which allows the extension of the upper pin 421 to slideaxially when the actuating pin 407 is pushed downward against spring 429similar to the clearance provided in the lower retaining ring 419 forthe extension of the lower pin 421 in the actuating pin 407. The pinactuating cylinder 424 also has a depression machined into the surfacewhich holds the poppet locking pin 428 initially in place, which allowsthe locking pin 428 to move upward releasing the poppet 405 when the pinactuating cylinder 424 is rotated.

The actuating pin 407 is shown in FIG. 18 in the fully retractedposition. Rod 420, the part which opens the tire core valve bydepressing the core valve pin, is guided by both the inner diameter ofthe actuating pin 407, and the inner diameter of the poppet assembly405. The rod 420 is assembled into the inner diameter of the activationpin 407 with a spring 426 with sufficient preload to depress the centerpin of the core valve in the tire stem. This spring insures full openingof the tire stem valve while at the same time accommodating the largetolerance for the location of the end of the core valve pin relative tothe tire stem (e.g., 0.010 inches above to 0.035 inches below the stemlip).

FIG. 19 shows the manually activated single pressure deflator valveafter activation. The entire activation pin assembly including theactivation pin 407, the adjustment knob 422, rubber seal washer 409, andpins 421 and 423 has been pushed downward and rotated to lock it intoplace. The core valve depressing rod 420 has also moved downward, butnot as much as the activating pin 407. The reason for this is that therod 420 is assumed to have contacted the center pin of the tire stemcore valve, depressed it completely until it reached bottom therebyopening the core valve fully, and then accommodated further motion ofthe actuating pin 407 by causing the spring 426 inside the actuator pin407 to compress against the lower pin 420. Note that the dust seal 409has also traveled with the actuating pin 407 maintaining a seal with theinner diameter of the rear housing 411.

The downward motion of the actuating pin 407 causes the tire core valveto open due to the action of the depressing rod 420 on the core valvepin. Since the locking pin 428 is still held in place by the pinactuator cylinder 424, the poppet 405 remains closed, although fullyexposed to tire pressure. At the same time the upper and lower pins 420in the activation pin 407 have traveled axially through the slots in pinactuation cylinder 424 and the lower retaining ring 419 respectively.All this has occurred due to the downward force exerted manually by theoperator on the adjustment knob 422.

As the operator turns the adjustment knob 422, along with the actuatingpin 407 and both upper and lower pins 421, the pin actuator cylinder 424also rotates causing the depression in the lower locking surface of thepin actuation cylinder 424 to align with the locking pin 428 allowing itto move upward releasing the poppet 405 as shown in FIG. 19. The valveis now fully operational and deflates the tire to the desired pressure.

At the same time, rotating the adjustment knob 422, along with theactuating pin 407, also rotates the extension of the lower pin 421 inthe activation pin 407 away from the slot in the lower retaining ring419. Thus, upon release of the adjustment knob 422 by the operator, theentire activating pin assembly 407, 422 and pins 421 and 430 is held inplace axially by the extension of the lower pin 421 bearing against thelower surface of the lower retaining ring 419. The valve is reset bysimply reversing the order of motion; i.e. the adjustment knob 422 isrotated in the opposite direction and allowed to move upward under theinfluence of either pressure or spring forces or both.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes and modifications in formand details may be made therein without departing from the spirit andscope of the invention.

What is claimed is:
 1. A valve for releasing fluid from a relativelyhigher pressure source to a relatively lower pressure receiver, saidvalve comprising:a housing having a first cavity, a second cavity, andan annular interior sealing surface, said first and second cavitiesbeing axially disposed and said annular interior sealing surface beingaxially disposed between them, said first cavity having connection meansfor operatively connecting to said source; an elastomeric ring; a poppetbeing disposed coaxially within said housing and having a substantiallycylindrical side wall, at least a portion of said side wall being anexternal sealing surface, said poppet also having fluid channeling meansfor channeling the fluid from said first cavity radially outward throughat least one orifice in said side wall, said poppet being axiallymovable at least between a closed position and a fully opened position,in said closed position, said elastomeric ring contacts said exteriorsealing surface and said interior sealing surface such that said firstcavity is hermetically sealed from said second cavity, in said fullyopened position, said orifice is disposed relative to said elastomericring such that fluid radially exiting said orifice deforms saidelastomeric ring outwardly forming a gap between said side wall and saidelastomeric ring, said gap enhancing the egress of fluid from said firstcavity to said second cavity; and actuation means for controlling saidpoppet's axial movement between said closed position and said fullyopened position.
 2. The valve according to claim 1, wherein said fluidchanneling means includes a radial flow nozzle, said elastomeric ringbeing elastically deformed by flow of fluid issuing thereagainst fromsaid radial nozzle.
 3. The valve of claim 2, wherein said elastomericring has first and second roughly hemispherical portions relative tosaid first and second cavities, said orifice being proximate to saidfirst portion when said poppet is in said closed position, said orificebeing proximate to said second portion when said poppet is in said fullyopened position.
 4. The valve according to claim 1, wherein saidconnection means includes means for mounting and sealedly connectingsaid first cavity to said container of pressurized fluid.
 5. The valveof claim 4, wherein said connecting means is adapted to mount onto avalve stem of a pneumatic tire.
 6. The valve according to claim 4,further comprising:means for inflating said pneumatic tire directlythrough said valve.
 7. The valve according to claim 1, wherein saidhousing comprises a sleeve of elastomeric material and at least one ventorifice that facilitates fluid communication between a portion of saidsecond cavity and said receiver, said sleeve covering said vent orifice,said sleeve being configured to minimize entry of foreign particles intosaid vent orifice.
 8. The valve of claim 4, further comprising:means forindicating fluid pressure in said container, said means for indicatingincluding an extension from said poppet, a portion of said extensionprotruding through said housing, said protrusion being indicative ofsaid fluid pressure in said container.
 9. The valve of claim 1, whereinat least a portion of said side wall includes means for restraining saidring seal from excessive deformation while said poppet is in said fullyopened position, said means for restraining being disposed proximate tosaid orifice on the first cavity side of said orifice.
 10. The valveaccording to claim 1, wherein said housing comprises restraining meansto restrict the axial movement of said elastomeric ring, saidrestraining means including an annular backup ring adjacent to saidelastomeric ring on its second cavity side.
 11. The valve according toclaim 1, wherein said actuating means comprises urging means for urgingsaid poppet axially toward said first cavity.
 12. The valve of claim 11,wherein said urging means comprises at least one spring connectedbetween said housing and said poppet.
 13. The valve of claim 12, whereinsaid urging means includes means for choosing a loading of said poppetfrom a plurality of predetermined loading magnitudes.
 14. The valve ofclaim 13, wherein said means for choosing includes means for registeringand holding a chosen spring-loading magnitude, said means forregistering and holding including a rotatable, cylindrical, sleeve cam.15. The valve according to claim 1, wherein said connection meansfurther comprises means for exposing said poppet to said pressurizedfluid by actuating a check valve to release said pressurized fluid intosaid first cavity.
 16. The valve of claim 15, furthercomprising:sequencing means for controlling the release of fluid fromsaid pressurized container having an outlet valve into said firstcavity, said sequencing means comprising:means of locking said poppet insaid closed position prior to fluid release; means of fully opening saidoutlet valve of said pressurized container to release said fluid intosaid first cavity; and means of releasing said poppet to permit axialmovement into said fully opened position.
 17. The valve according toclaim 1, wherein said actuating means include force-balancing means forforce-balancing said poppet in its relative axial position in saidhousing, said force-balancing means including:means for spring loadingsaid poppet, said means for spring loading including at least one springdisposed between said housing and said poppet to exert a spring force onsaid poppet toward said first cavity; and means for exposing said firstcavity to said fluid of said pressurized container, and thereby defininga pressure force against said poppet toward said second cavity, thedifference between said spring force and said pressure force beingdefined as a force difference, said force balancing means beingoperative in moving said poppet axially in a direction to diminish saidforce difference.
 18. The valve of claim 1, wherein said poppet has anaxial extension toward said second cavity, said extension protrudingfrom said housing and including a conduit for conducting fluid from saidfirst cavity through said extension, said conduit including means forstopping fluid flow therethrough.
 19. A valve for relieving excess fluidpressure in a container of pressurized fluid to a preset pressure, thevalve comprising:a housing having a cavity and therein an internal sealsurface of substantially cylindrical form, said housing including a sealthat is ring-shaped and formed of an elastomeric material, said sealseating upon said internal seal surface and being restrained fromsubstantial axial movement, said seal being resiliently and elasticallydeformable; and, a poppet coaxially movably borne within said cavity,said poppet having an external surface of cylindrical shape that isdisposed coaxially within said cavity, said external surface, ring sealand internal surface cooperating to form a seal, said poppet having afirst and a second axial end, said poppet including means for bypassingsaid seal, said means for bypassing including a passage for fluidbetween said first axial end and said external surface, said passageincluding at least one face conduit and a channel connecting therefromsubstantially radially through said external surface, said channelincluding means for deforming said seal to deform said seal and form agap between a portion of said seal and said external surface when saidpoppet is in a fully opened position.
 20. A valve for relieving fluidpressure in a container of pressurized fluid from excess pressure to apreset pressure, the valve comprising:a housing having a first cavityand a second cavity, said cavities being disposed axially andadjacently, said housing including a ring-shaped seal and a seattherefor disposed between said cavities; a poppet coaxially bornebetween said first cavity and said second cavity, said poppet beingcoaxially movable to fully opened and closed positions, said poppethaving an external sealing surface that is substantially cylindrical forsealing against said ring-shaped seal when said poppet is in said closedposition thereby hermetically sealing said first cavity from said secondcavity; the valve being characterized by a gap between said externalsealing surface and a portion of said ring-shaped seal that faces towardsaid external sealing surface while said poppet is in said fully openedposition; and, common means for channeling relief flow past saidring-shaped seal from said first cavity to said second cavity and fordeforming said seal to promote widening of said gap while the valve isoperative in relieving excess pressure in said container.